I want to mock a constructor into method.
public String generaID() {
GeneraIDParaEntidadCliente aux = new GeneraIDParaEntidadCliente(nombre, registro
you can send mocked objects as paramemters to your class constructor, form example:
// define you object
public MainClassObj instanceClass;
// mock input parameter
MYClassObj mockedObj = Mockito.mock(MYClassObj.class);
// call construvtor with mocked parameter
instanceClass = new instanceClass(mockedObj);